China confirmed a sixth death from a lesser known H7N9 strain of the bird flu virus, Friday. About 14 people infected with the deadly virus remained critically ill even as the authorities slaughtered over 20,000 birds at the Shanghai poultry market.

State news agency Xinhua said the Huhuai market for live birds in Shanghai had been shut down after the authorities late Thursday detected the H7N9 virus in live pigeons in the market. Authorities also suspended operations in another two markets in the city as a precautionary measure.

All the reported infections of H7N9 avian influenza virus were in eastern China. The first cases were reported Sunday by the health authorities who announced two deaths from the infection in Shanghai in Jiangsu province. Xinhua said six cases have been confirmed in Shanghai, four in Jiangsu, three in Zhejiang and one in Anhui.

A 64-year-old man in Zhejiang province was the latest victim to the virus that had never been passed to humans before, Xinhua reported Friday. Most of the infected had direct contact with poultry and were butchers, breeders or transporters of poultry.

Health officials believe the victims contracted the deadly virus strain directly from the live poultry and its ability to spread among humans is yet to be confirmed. However, the scientists are closely monitoring the situation to see if the new flu poses a threat to the public health or could spark a global pandemic, the Associated Press reported.

The virus was found in samples of pigeons that were being sold for meat in the Shanghai’s market. Chinese authorities Friday culled all the birds in the poultry market to control further infection. Certain species of pigeons are consumed as meat by the Chinese and live pigeons are sold in the markets across the country.

Experts have warned the new virus has the potential to be a greater threat as it can infect birds without causing the disease, making it harder to detect than the familiar H5N1 bird flu virus.

"In the past usually you would see chickens dying before any infections occurred in humans, but this time we've seen that many species of poultry actually have no apparent problems, so that makes it difficult because you lose this natural warning sign," said David Hui, an infectious diseases expert at the Chinese University of Hong Kong, AP reported.

Although there is no known vaccine for the new H7N9 virus, preliminary test results suggest the new flu strain responds to treatment with Roche's drug Tamiflu and GSK's Relenza, according to the WHO.

Markets Tumble Over New Bird Flu Concern

Panic over the new strain of virus infections affecting the local economy sent the Hong Kong shares to a four-month-low in early trade Apr.5.

"The bird flu issue is at the top of people's minds now," said Alfred Chan, chief dealer at Cheer Pearl Investment in Hong Kong, Reuters reported.

The news bird flu outbreak is feared to adversely affect the poultry and tourism allied sectors in China. Several consumers told Reuters that they are keeping away from the poultry markets after reports of mounting death toll.

"I'm only getting my groceries at the large supermarkets now because I don't think it is safe to visit the wet markets anymore," 38-year-old homemaker Shao Linxia said, adding that she has also stopped buying poultry since news of the bird flu surfaced.

"We all remember SARS and how quickly it could spread, so we are obviously worried."